Radiator system for internal combustion engine

ABSTRACT

A liquid coolant radiator for the cooling system of a heatgenerating engine and specifically an internal combustion engine with the radiator including an inlet header, an outlet header, tubes interconnecting the headers for flow of liquid in a flow path through the engine and radiator in which the radiator portion of the flow path includes the inlet header, tubes and outlet header, a tank for separating entrained gas such as air, leaked combustion gases and the like with the tank having a space for receiving the gas and from which the gas can then be vented to the atmosphere, a tube interconnecting the tank and the coolant flow path for diverting some of the coolant with the entrained gas into the tank and a fluid flow device for inducing mixed liquid and entrained gas flow into the tank as by applying a suction in order that the gas may be separated from the coolant in the tank and vented to the atmosphere without disturbing the coolant flow in the coolant flow path.

United States Patent [72] Inventors Joseph H. Anders;

Daniel J. Bosch, both of Racine, Wis. [21] Appl. No. 889,033 [22] Filed Dec. 30, 1969 [45] Patented Nov. 30, 1971 [73] Assignee Modlne Manuiacturing Company [54] RADIATOR SYSTEM FOR INTERNAL COMBUSTION ENGINE 10 Claims, 4 Drawing Figs. [52] 11.8. C1 l23/41.54, 123/41.27, 123/4151, 165/110 [51] Int. Cl ..F28d 15/00, FOlp 3/22 [50] Field of Search 123/4154, 41.51,41.27; 165/110 [56] References Cited UNITED STATES PATENTS 1,658,934 2/1928 Muir 123/4154 2,170,214 8/1939 Morrow et a1. 165/110 2,428,373 10/1947 Lloyd 123/4151 3,051,450 8/1962 White et a1. 165/110 Primary Examiner-Laurence M Goodridge Assistant Examiner-Cort Flint Attorney-Hofgren, Wegner, Allen, Stellman & McCord ABSTRACT: A liquid coolant radiator for the cooling system of a heat-generating engine and specifically an internal combustion engine with the radiator including an inlet header, an outlet header, tubes interconnecting the headers for flow of liquid in a flow path through the engine and radiator in which the radiator portion of the flow path includes the inlet header, tubes and outlet header, a tank for separating entrained gas such as air, leaked combustion gases and the like with the tank having a space for receiving the gas and from which the gas can then be vented to the atmosphere, a tube interconnecting the tank and the coolant flow path for diverting some of the coolant with the entrained gas into the tank and a fluid flow device for inducing mixed liquid and entrained gas flow into the tank as by applying a suction in order that the gas may be separated from the coolant in the tank and vented to the atmosphere without disturbing the coolant flow in the coolant flow path.

RADIATOR SYSTEM FOR INTERNAL COMBUSTION ENGINE One of the features of this invention is to provide a liquid coolant radiator for the cooling system of a heat-generating engine having positive flow inducing means for directing some of the coolant from its normal flow path into a quiescent tank or chamber in which the gas is separated from the coolant and the gas vented to the atmosphere.

Another feature of the invention is to provide a liquid coolant radiator having a gas separating container or tank that is supplied with liquid from the coolant flow path at all times during engine operation.

Other features and advantages of the invention will be apparent from the following description of certain embodiments thereof taken in conjunction with the accompanying drawings. Of the drawings:

FIG. 1 is a semidiagrammatic elevational view of an internal combustion engine and a coolant flow path therefor including a heat-dissipating air-cooled radiator.

FIG. 2 is a semidiagrammatic elevational view illustrating a second embodiment of a radiator embodying the invention.

FIG. 3 is a view similar to FIG. 2 but illustrating a third embodiment of the invention.

FIG. 4 is a view similar to FIG. 2 but illustrating a fourth embodiment of the invention.

In the embodiment of FIG. I there is illustrated an internal combustion engine of the ordinary type that includes a customary liquid coolant portion having an ordinary powerdriven coolant-circulating pump 11. The cooling system within the engine 10 has an inlet 12 leading to the pump 11 and an outlet 13 leading from the cooling section of the engine.

The coolant to and from the engine 10 is conducted in a flow path that has in it an air-cooled radiator 14. This radiator as illustrated in the embodiment of FIG. 1 comprises an inlet header 15, an outlet header 16, parallel tubes 17 interconnecting the headers for flow of liquid in a flow path that includes the inlet header l5, outlet header I6 and the intervening tubes 17.

Coolant and entrained gas is directed from the engine outlet 13 through a liquid line 18 to the top of the inlet header as indicated at 19. Located in the liquid line 18 is a customary heat-operated thermostatic valve 20 which opens and closes to circulate liquid through the radiator 14 as a result of coolant temperature in the engine 10. The bottom of the outlet header I6 is connected by means ofa liquid line 21 to the inlet 12 to the liquid-circulating pump 11 of the engine.

Associated with the radiator 14 is a fluid-confining means 22 illustrated in FIG. I as a tank that is separated from the outlet header 16 by a common dividing wall 23. This tank 22 is for separating entrained gas from the coolant liquid and as a gas-receiving part 24 has a head space at the top of the tank 22 and a liquid-receiving part 25 at the bottom for receiving the coolant liquid 26. As can be seen, the tank 22 provides a quiet space in which the more buoyant entrained gas has time to separate from the liquid 26 and collect as indicated at 27 as a gas with the liquid and gas having a liquid interface 28 therebetween.

In the radiator of FIG. 1 there is also provided a liquid flow means in the form of a small tube 29 interconnecting the confining means tank 22 and the liquid flow path. In the illustrated embodiment this connecting is provided by having the tube 29 entrance end 30 at the top of the outlet header I6 and exhausting at an exit end 31 at the top of gas head space 24.

In order to provide fluid flow, here the mixed coolant liquid and entrained gas, from the flow path into the separating tank 22 there are provided means for inducing fluid flow in the tube 29 from the flow path into the tank 22 or in the direction of the arrows of FIG. I. This means for inducing fluid flow therefore continually draws a portion of mixed coolant and entrained gas from the flow path and separates the gas from the coolant after which the coolant is returned to the flow path in the manner illustrated hereinafter.

In the embodiments shown in the drawings this fluid flow inducing means comprises a venturi tube aspirator 32 that may be positioned within the gas-confining head space 24 of tank 22 or outside tank 22 and is supplied with mixed liquid and coolant by way of a first supply line 33 from the coolant portion of the engine 10. This line 33 leads through the venturi tube 32 to create a suction therein in the customary manner and the tube 29 from the coolant flow path portion of the radiator is connected to the throat of the venturi in the customary manner so that flow of liquid from the engine by way of the line 33 through the venturi tube draws a suction in the tube 29 to cause fluid flow therethrough in the direction indicated. The coolant and entrained gas from the flow path header l6 and from the engine by way of the tube line 33 mix in the venturi tube 32 and are exhausted out the exit 31 which is positioned at the top of the gas head space 24.

The common dividing wall 23 that separates the fluid confining tank 22 from the outlet header 16 is a vertical wall in the embodiment of FIG. 1 because the radiator 14 therein is a cross tube radiator with vertical headers 15 and 16. Located adjacent the bottom of this wall 23 are means embodied in the opening 34 for providing fluid flow between the liquid receiver tank 22 and the one header which in the FIG. 1 embodiment is the outlet header 16.

In order to return the liquid 26 which is substantially free of entrained gas to the coolant flow path there is provided a return line 38 from the bottom of the tank 22 to the inlet 12 of the engine coolant circulating pump 11. In order to vent the separated gas in the gas space 24 to the atmosphere there is provided a customary liquid fill and pressure relief valve radiator cap 35.

In each of the embodiments illustrated the fluid flow line from the venturi tube 32 and leading to the exit 31 includes a fluid trap illustrated herein as a U-tube 36. This trap has its inlet end connected to the outlet of the aspirator 32 as illustrated, its bottom immersed in the coolant liquid 26 in the lower regions of the gas-separating tank 22 and its outlet end comprising the exit 31 at the top of the gas-containing head space 24.

In order to drain the radiator 14 there is provided a drain valve 87 in the bottom of the radiator that is designed for simultaneous drainage of the bottom of the U-tube 36 by way of a line 37 and the bottom of the fluid-confining tank 22. Because of the provision of the bottom opening 34 the drain valve 87 functions to drain the entire radiator 14 when desired.

Any type dual-drain valve arrangement desired can be used and an excellent valve is shown and described in the copending application of Donald J. Frost Ser. No. 13,008, filed Feb. 20, 1970, assigned to the same assignee as the present application.

In the embodiment of FIG. 1 there is provided a further or second supply line 39 for coolant from the engine I0 and leading to the bottom of the fluid-confining tank 22. The two lines 33 and 39 serve to direct liquid with entrained gas into the gasseparating tank 22 when the thermostat valve 20 is closed so that no coolant is flowing through the radiator 14. When the valve 20 is open so that coolant is flowing through the supply line 18 to the radiator, coolant flow in line 39 can flow in either direction or can be completely stagnant depending upon the normal flow conditions in the specific engine-cooling radiator system itself. In other words, with the thermostat valve 20 open flow through the line 39 becomes unimportant. On the other hand, coolant flow from the engine through line 33 and through the venturi aspirator 32 occurs at all times whether or not the thermostat valve 20 is opened or closed. This is the case in order that there will always be a suction on the line 20 so as to continuously withdraw s small but steady amount of coolant with entrapped gas from the flow path for separation of the gas.

During the operation of the embodiment of FIG. I coolant is pumped through the engine 10 by the coolant pump II in the customary manner. When the temperature conditions of the coolant are such that the valve 20 is open coolant will be directed from the engine through line 18 to the top of the inlet header as indicated at 19. Liquid coolant from this header 15 then flows in parallel through the spaced tubes 17 where it is cooled in the customary manner by air contact with the tubes and the spaced interconnecting fins 40. The tubes 17 empty into the outlet header l6 and the coolant is returned from the bottom of this header 16 by the line 21 to the inlet 12 of the coolant circulating pump 11.

Regardless of whether the valve 20 is open or closed coolant is also directed from the cooling system portion of the engine 10 through the line 33 into and through the venturi tube 32 and from there through the liquid trap 36 into the top of the gas-containing head space 24. This flow of coolant through the venturi tube 32 sets up a suction in the line 29 which thereby continuously draws a small amount of mixed coolant and entrained gas from the top of the header 16, mixes it with the coolant and gas from the engine line 33 and exhausts the mixture out the exit 31. When the valve 20 is closed coolant and entrained gas is simultaneously supplied to the bottom of the tank 22 through the line 39.

In the tank 22 where flow conditions are relatively quiet entrained gas rises from the coolant within this tank and collects in the gas head space 24. This gas is then vented to the atmosphere in the customary manner through the radiator cap 35. During this operation of the engine 10 coolant with resulting greatly reduced gas content is returned to the engine-cooling system by way of the line 38 leading to the inlet 12 of the liquid-circulating pump 11. This deaerated liquid coolant return line 38 may or may not be used, as desired, as in its absence coolant 26 would be returned to the engine by way of the bottom opening 34 and the main return line 21 from the bottom of the outlet header 16.

In the embodiment of FIG. 1 the combined liquid flow rates in lines 29, 33 and 38 when used are such that the liquid level in tank 22 is below the top of this tank and well above the bottom of the U-tube 36.

The venturi tube 32 due to the suction set up therein draws only a relatively small volume flow of coolant and entrained gas through the line 29. Thus it serves continuously to induce fluid flow in this line so that the entrained gas can be removed. In addition, the venturi tube 32 reduces the time for deaerating the liquid coolant on start-up of the engine after the engine and associated fluid flow lines have been initially filled with coolant. It also improves the efficiency of the deaeration as it continuously applies a suction to the coolant and it insures that the radiator 14 will be full of liquid coolant at all times as entrained gas is continuously removed. In initially filling the radiator 14 through the cap 35 in the customary manner the radiator is of course filled from the bottom by reason of the provision of the bottom opening 34 in the wall 23 and also through lines 38 and 21 when bottom opening 34 is small. During this filling from the bottom the line 29 leading to the venturi tube 32 as well as the tube itself serves as a vent to permit the escape of air from the top of the radiator through the top cap 35.

The trap embodied in the U-tube 36 serves to prevent the coolant level in the cooling system falling when the engine 10 is stopped. Thus when this occurs the pump 11 also stops which means that pumped coolant is no longer forced through line 33 which is the coolant supply line from the engine to the tank 22. Because the U-tube 36 maintains a liquid trap even when liquid is no longer supplied through the main inlet flow line 33 no air can enter the system so that the liquid level in the radiator 14 cannot fall. Because the liquid in the radiator cannot fall the coolant system including that portion of the engine 10 remains filled at all times whether or not the engine is running and so long as there is no malfunction of the system. Then, on restarting the engine the cooling of the engine is immediate as there is no waiting for the cooling system to fill with coolant as it is already full from the previous operation.

After the engine 10 has been running and the hot engine is shut off, steam sometimes tends to form in the cooling system and thus this will force hot coolant back up through line 38 and out the pressure relief valve (not shown) in the radiator cap 35. When this occurs in the ordinary engine it is known as afterboil. In order to prevent this a check valve 41 may be used in the coolant return line 138 as illustrated in the embodiment of FIG. 2. Due to the presence of this check valve 41 which prevents reverse flow in the line 138 which is otherwise equivalent to line 38 of FIG. 1, steam in the engine can flow from the engine through line 33 into the head space 24 and from there to ambient through the pressure relief valve radiator cap 35. This steam of course enters the space 24 by way of the U-tube 36 so that the tube is in the process blown free of liquid. Because of this removal of liquid from the U-tube the coolant in the system will drop to a somewhat lower level because gases in the space 24 will flow into the open end 31 of the U-tube and from the tube through lines 33 and 29 which lead to the engine coolant system and radiator, respectively. The result of this is that every time an afterboil occurs it is necessary to remove the air that enters the system. However, with the structure of this invention the air is removed rapidly and efiiciently in the manner previously described by the suction created in the venturi tube 32. As is well known, afterboils are infrequent and seldom occur if the engine is shut down properly after operation.

The embodiment of FIG. 2 is quite similar to that of FIG. 1 except in FIG. 2 the inlet header is adjacent the fluidseparating tank 22 and the outlet header 116 is on the opposite side of the radiator 114. Coolant with entrained gas is supplied to the inlet header through a line 118 that corresponds to the line 18 in the first embodiment with this line also containing the thermostat valve 20. Liquid from the outlet header 116 in this embodiment is returned to the engine by line 121 which is similar in operation to line 21 ofFlG. 1.

In the embodiment of FIG. 3 the substantially gas-free return line 38 is omitted and this liquid 126 is returned to the engine by the above described return line 21 leading from the outlet header 16. In this embodiment of FIG. 3 the opening 134 in the dividing wall 123 is made somewhat larger to accommodate this increased liquid flow. All other elements of the embodiment of FIG. 3 are the same as described.

In the embodiment of FIG. 4 there is provided a fourth tank 42 adjacent the inlet header 15 and divided therefrom by a common wall 43. This fourth tank 42 which also serves as a reservoir for separating entrained gas from coolant includes a lower liquid-receiving part 44 adapted to contain liquid 45 and an upper gas-receiving part 46. The two gas receiving parts 24 and 46 on opposite ends of the header are interconnected by a gas flow line 47 while the two liquid bodies 26 and 45 are interconnected by a liquid line 48. Thus in this embodiment there are two gas and liquid separation tanks on opposite ends of the radiator and pressure therein is equalized by the interconnecting gas line 47 and liquid line 48. This embodiment therefore provides additional reserve coolant supply and the pressure balance lines 47 and 48 maintain equal reserve coolant levels 28 and 49 in the two tanks. This embodiment of FIG. 4 is also provided with liquid supply lines 33 and 39, inlet line 18 and contained thermostat valve 20 and outlet line 21 as previously described.

Having described our invention as related to the embodiments shown in the accompanying drawings, it is our intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the ap pended claims.

We claim:

1. A liquid coolant radiator for the cooling system of a heatgenerating engine, comprising: a liquid coolant inlet header; a liquid coolant outlet header; tubes interconnecting said headers for flow of mixed gas and coolant liquid in a flow path means that includes said inlet header, tubes and outlet header; fluid-confining means for separating entrained gas from coolant liquid having a gas receiver part; fluid flow means interconnecting said confining means and said flow path means;

positive flow-inducing means for inducing fluid flow in said fluid flow means from said flow path means to said confining means thereby flowing mixed coolant liquid and gas into said confining means from said flow path means; an inlet conduit means to said inlet header for flow of liquid thereto from said engine; a liquid flow control thermostat open and shut valve means in said inlet conduit means for controlling fluid flow in said flow path means; and fluid conduit means from said engine to said fluid-confining means bypassing said valve for flow of fluid t0 the fluid-confining means from said engine even when said valve is closed.

2. A liquid coolant radiator for the cooling system of a heatgenerating engine, comprising: a liquid coolant inlet header; a liquid coolant outlet header; tubes interconnecting said headers for flow of mixed gas and coolant liquid in a flow path means that includes said inlet header, tubes and outlet header; fluid-confining means for separating entrained gas from coolant liquid having a gas receiver part; fluid flow means interconnecting said confining means and said flow path means, said fluid flow means including a U-tube trap having an entrance connected to said fluid flow means and an exit in said fluid-confining means; positive flow-inducing means for in ducing fluid flow in said fluid flow means from said flow path means to said confining means from said flow path means; and drain means for simultaneously draining said trap and said radiator.

3. The radiator of claim 1 wherein said positive flow-inducing means comprises aspirator means in said fluid conduit means connected to said fluid flow means for creating a suction in said fluid flow means by liquid flowing through said fluid conduit means and aspirator from said engine.

4. The radiator of claim 1 wherein said positive flow-inducing means comprises aspirator means in said fluid conduit means connected to said fluid flow means for creating a suction in said fluid flow means by liquid flowing through said fluid conduit means and aspirator from said engine and said fluid flow means comprises a tube having an entrance adjacent the top of said flow path means and an exit adjacent the top of said gas receiver part.

5. The radiator of claim 3 wherein said aspirator is positioned in said gas receiver part.

6. The radiator of claim 3 wherein there is provided a liquid trap having an entrance connected to the exit from the aspirator to receive fluid therefrom and an exit from the trap adjacent to the top of said gas receiver part.

7. The radiator of claim 2 wherein said trap is located substantially entirely in said fluid-confining means, said drain means drains said fluid-confining means, and there is provided a fluid flow opening between said fluid-confining means and said flow path means for said draining of the radiator.

8. The radiator of claim 1 wherein said fluid-confining means includes a liquid receiver part beneath said gas receiver part for buoyant separation and collection of said entrained gas in said gas receiver part, and said fluid conduit means comprises a first supply line to said gas receiver part and a second supply line to said liquid receiver part.

9. The radiator of claim 8 wherein said positive flow-inducing means comprises aspirator means in said first supply line connected to said fluid flow means for creating a suction in said fluid flow means.

10. The radiator of claim 9 wherein there is provided a liquid trap having an entrance connected to the exit from the aspirator to receive fluid therefrom and an exit from the trap adjacent to the top of said gas receiver part 

1. A liquid coolant radiator for the cooling system of a heatgenerating engine, comprising: a liquid coolant inlet header; a liquid coolant outlet header; tubes interconnecting said headers for flow of mixed gas and coolant liquid in a flow path means that includes said inlet header, tubes and outlet header; fluidconfining means for separating entrained gas from coolant liquid having a gas receiver part; fluid flow means interconnecting said confining means and said flow path means; positive flow-inducing means for inducing fluid flow in said fluid flow means from said flow path means to said confining means thereby flowing mixed coolant liquid and gas into said confining means from said flow path means; an inlet conduit means to said inlet header for flow of liquid thereto from said engine; a liquid flow control thermostat open and shut valve means in said inlet conduit means for controlling fluid flow in said flow path means; and fluid conduit means from said engine to said fluid-confining means bypassing said valve for flow of fluid to the fluid-confining means from said engine even when said valve is closed.
 2. A liquid coolant radiator for the cooling system of a heat-generating engine, comprising: a liquid coolant inlet header; a liquid coolant outlet header; tubes interconnecting said headers for flow of mixed gas and coolant liquid in a flow path means that includes said inlet header, tubes and outlet header; fluid-confining means for separating entrained gas from coolant liquid having a gas receiver part; fluid flow means interconnecting said confining means and said flow path means, said fluid flow means including a U-tube trap having an entrance connected to said fluid flow means and an exit in said fluid-confining means; positive flow-inducing means for inducing fluid flow in said fluid flow means from said flow path means to said confining means thereby flowinG mixed coolant liquid and gas into said confining means from said flow path means; and drain means for simultaneously draining said trap and said radiator.
 3. The radiator of claim 1 wherein said positive flow-inducing means comprises aspirator means in said fluid conduit means connected to said fluid flow means for creating a suction in said fluid flow means by liquid flowing through said fluid conduit means and aspirator from said engine.
 4. The radiator of claim 1 wherein said positive flow-inducing means comprises aspirator means in said fluid conduit means connected to said fluid flow means for creating a suction in said fluid flow means by liquid flowing through said fluid conduit means and aspirator from said engine and said fluid flow means comprises a tube having an entrance adjacent the top of said flow path means and an exit adjacent the top of said gas receiver part.
 5. The radiator of claim 3 wherein said aspirator is positioned in said gas receiver part.
 6. The radiator of claim 3 wherein there is provided a liquid trap having an entrance connected to the exit from the aspirator to receive fluid therefrom and an exit from the trap adjacent to the top of said gas receiver part.
 7. The radiator of claim 2 wherein said trap is located substantially entirely in said fluid-confining means, said drain means drains said fluid-confining means, and there is provided a fluid flow opening between said fluid-confining means and said flow path means for said draining of the radiator.
 8. The radiator of claim 1 wherein said fluid-confining means includes a liquid receiver part beneath said gas receiver part for buoyant separation and collection of said entrained gas in said gas receiver part, and said fluid conduit means comprises a first supply line to said gas receiver part and a second supply line to said liquid receiver part.
 9. The radiator of claim 8 wherein said positive flow-inducing means comprises aspirator means in said first supply line connected to said fluid flow means for creating a suction in said fluid flow means.
 10. The radiator of claim 9 wherein there is provided a liquid trap having an entrance connected to the exit from the aspirator to receive fluid therefrom and an exit from the trap adjacent to the top of said gas receiver part. 